JMIR Publications

ABSTRACT

Background:

Infodemiology is an emerging field of research that focuses on using user-generated health-related content, such as from social media sources to help improve public health. Twitter has become an important venue for studying emerging patterns in public health issues like substance use because they reflect population-level trends in real-time and display messages generated directly by users, giving a uniquely personal voice to analyses. Over the past year, several states in the United States (U.S.) have passed legislation to legalize recreational use of cannabis and the federal government in Canada has done the same. Currently, there is a lack of study examining the sentiment and content of Tweets about cannabis with the recent changes in cannabis laws from 2017 to 2019 in North America.

Objective:

To examine differences in the sentiment and content of cannabis-related Tweets by state cannabis laws, and to examine differences in sentiment between the U.S and Canada.

Methods:

In total, 1,200,127 cannabis-related tweets were collected from January 1, 2017 to June 17 2019 using the Twitter application programming interface. Tweets then were grouped geographically based on cannabis legal status in the locations the Tweets came from. Sentiment scoring for the Tweets was done with VADER Sentiment, and differences in sentiment were tested using Tukey adjusted two-sided pairwise comparisons. Topic analysis to determine the content of Tweets was done using Latent Dirichlet Allocation in Python, using a Java implementation, LdaMallet, with Gensim wrapper.

Results:

Significant differences were seen in Tweet sentiment between U.S. states with different cannabis policies, as well as between the U.S. and Canada. In both cases, restrictive state policy environments were associated with more negative Tweet sentiment. Six key topics were found in recent Tweet content: fun and recreation; daily life; transactions; places of use; medical use and cannabis industry; and legalization. The keywords representing content of Tweets also differed between the U.S. and Canada.

Conclusions:

Knowledge about how cannabis is being discussed online, and geographic differences that exist in these conversations may help to inform public health planning and prevention efforts. Public health education about how to use cannabis in ways that promote health and minimize harms may be especially important in places where cannabis is legal for recreational and medical use.